Capillarity Driven Flow Of Propellant Liquids In Colloidal Satellite Thrusters

The objective of this project is to develop colloidal thrusters capable of producing the thrust levels required to overcome drift and maintain individual microsatellites at their assigned positions. In the Phase I research on this project, we showed that the use of capillarity driven flow of non-volatile propellant liquid through a porous matrix or wick could produce extremely stable electrosprays in vacuum of charged droplets. Inherent in this use of wick injection is that the flow rate of propellant liquid, and thus the thrust level for a particular thruster, is determined entirely by the applied voltage without any need for additional flow rate control circuitry. Moreover, this inherent simplicity, relative to other colloidal propulsion systems, means that multiplexing of such wick injectors is simple and straight-forward so that any desired level of thrust over a wide range can be achieved simply by varying the number of these simple wick thrusters. The objective of the proposed Phase II research is to implement the results of our Phase I research by designing, constructing and testing prototype wick thrusters with both conventional needle designs and to investigate similar applications using MEMS technology.